David Haye's superior boxing skills will make the difference in his grudge match with Dereck Chisora, according to Audley Harrison.

Haye can point to a decorated amateur career and a spell as world heavyweight champion in the pro game, while Chisora has found victories tough to come by at the top level: he has tasted defeat against Vitali Klitschko, Robert Helenius and Tyson Fury recently.

And Harrison feels that Haye's more refined style of boxing will be the deciding factor when the two Londoners face off at Upton Park on July 14.

"I have to go with Haye [to beat Chisora], I have to go with the boxer and the puncher rather than a slugger," Harrison, who lost to Haye in November 2010, told ESPN.

The Haye v Chisora contest has been sanctioned by the Luxembourg Boxing Federation, as neither man possesses a British licence. Harrison is refusing to be drawn on the rights and wrongs of that situation - although he did use the example of Lennox Lewis to defend the widely-condemned press conference brawl between Haye and Chisora in February.

"I don't want to get involved on whether it should or shouldn't happen," Harrison said. "What I would say is that my greatest idol, one of the best who ever did it, Lennox Lewis, had two fights at press conferences. The Mike Tyson stuff, people said, 'How scandalous is this?' Then there was the Hasim Rahman stuff, [when] they fought in a studio. It didn't take nothing from Lennox Lewis because sometimes you have to defend your honour."

Harrison returns to the ring for the first time since losing to Haye when he faces Ali Adams in Essex on Saturday. Harrison has vowed to retire if he does not triumph.

After enduring a tricky start to his Manchester United career, perhaps it is fair that Marcos Rojo celebrated so boisterously as he watched his first professional club Estudiantes beat fierce rivals Gimnasia